The subject of this thesis was the design of a new fault tolerant system that is able to operate the controller of an automotive steering servo system. With the rise of novel technologies in the automotive industry (automated parking, self-driving, etc.) the requirements to be met have also changed. The currently most commonly used fail-stop systems are being replaced by fail-operational systems.
My task was to develop a system based on the TMR architecture that is capable of continuous operation after one fault in the system, with the use of three redundant hardware-software channels. This includes the design of the physical structure and the development and testing of the algorithms needed for the system.
In this thesis, first the industrial technologies most commonly used for the design of fault tolerant systems are introduced and then the conditions that need to be satisfied to design a triple modular redundant system are presented in detail. After this the system design and the physical test environment is presented. One of the most important requirements of the system is that the three basically asynchronous channels must be operating in a synchronized fashion. The quality of the synchronization has a huge influence on the operability of the system. Because of that we present a formal mathematical proof of the correctness of the synchronization algorithm. From the functional testing of the system we conclude that the working prototype satisfies all of the initial requirements.
If the designed system proves to be working after more extensive testing, the system may be introduced into real-life automotive steering systems.